1. Technical Field
The present invention relates to a semiconductor integrated circuit, and in particular, to a pumping voltage generating apparatus of a semiconductor integrated circuit.
2. Related Art
A semiconductor integrated circuit, for example, a semiconductor memory apparatus requires a voltage that is higher than an external voltage VDD in order to be sufficiently driven, and such a high voltage is generated by pumping the external voltage. Recently, a semiconductor memory apparatus having low current consumption has been developed with the trend in reducing the external voltage level. For this reason, a larger amount of pumping an external voltage is required to generate a high voltage. When the amount of pumping is increased, the current consumption of the semiconductor integrated circuit is correspondingly increased, which results in an increase in the size of a pumping circuit.
Recently, separate power for generating a pumping voltage supplied from the outside is provided to the semiconductor memory apparatus in order to generate a pumping voltage (hereinafter, external pumping voltage). Further, an internal pumping voltage that is almost as twice as much the external pumping voltage is generated by pumping the external pumping voltage, and a general pumping voltage is generated by dropping the external pumping voltage.
However, the internal pumping voltage that is almost as twice as much the external pumping voltage may cause a stress in the semiconductor integrated circuit, especially, a semiconductor memory apparatus. Further, stress may affect a burn-in test process, which may cause a defective semiconductor integrated circuit and malfunction of a circuit, and as a result, reliability is reduced.